Hi Chris,

maybe better solution:

supposing, that you will store your two numbers in a1 (=3) and b1 (=4),
you can re-write the formula to be:
=DCOUNTA(Query!$A$1:$C$50319,Query!$A$1,indirect(" Calculations!$DM$"&a1&":$DP$"&b1))

Regards,
Ivan